ln(2x-(21)/x)<= 0

解

ln (2 x - \frac{21}{x}) \leq 0

- \frac{21}{2} < x \leq - 3 or \frac{21}{2} < x \leq \frac{7}{2}

区間表記

(- \frac{21}{2}, - 3] \cup (\frac{21}{2}, \frac{7}{2}]

十進法表記

- 3.24037 \dots < x \leq - 3 or 3.24037 \dots < x \leq 3.5

解答ステップ

ln (2 x - \frac{21}{x}) \leq 0

対数の規則を適用する

2 x - \frac{21}{x} \leq 1 and 2 x - \frac{21}{x} > 0

2 x - \frac{21}{x} \leq 1 and 2 x - \frac{21}{x} > 0 : - \frac{21}{2} < x \leq - 3 or \frac{21}{2} < x \leq \frac{7}{2}

- \frac{21}{2} < x \leq - 3 or \frac{21}{2} < x \leq \frac{7}{2}